1gqi
From Proteopedia
STRUCTURE OF PSEUDOMONAS CELLULOSA ALPHA-D-GLUCURONIDASE
Overview
Alpha-glucuronidases, components of an ensemble of enzymes central to the recycling of photosynthetic biomass, remove the alpha-1,2 linked 4-O-methyl glucuronic acid from xylans. The structure of the alpha-glucuronidase, GlcA67A, from Pseudomonas cellulosa reveals three domains, the central of which is a (beta/alpha)(8) barrel housing the catalytic apparatus. Complexes of the enzyme with the individual reaction products, either xylobiose or glucuronic acid, and the ternary complex of both glucuronic acid and xylotriose reveal a "blind" pocket which selects for short decorated xylooligosaccharides substituted with the uronic acid at their nonreducing end, consistent with kinetic data. The catalytic center reveals a constellation of carboxylates; Glu292 is poised to provide protonic assistance to leaving group departure with Glu393 and Asp365 both appropriately positioned to provide base-catalyzed assistance for inverting nucleophilic attack by water.
About this Structure
1GQI is a Single protein structure of sequence from Cellvibrio japonicus. Full crystallographic information is available from OCA.
Reference
The structural basis for catalysis and specificity of the Pseudomonas cellulosa alpha-glucuronidase, GlcA67A., Nurizzo D, Nagy T, Gilbert HJ, Davies GJ, Structure. 2002 Apr;10(4):547-56. PMID:11937059 Page seeded by OCA on Fri May 2 17:53:41 2008
